What is one way the tilt of the earth's axis causes the seasons? a. the tilt of the axis brings the earth closer to the sun in summer. b. the tilt causes the amount of time the sun shines each day to be greater on the part of the earth where it is winter and less where it is summer. c. the tilt causes the earth's rotation to slow down in the summer and speed up in the winter. d. the tilt causes the sun to shine more directly on the part of the earth where it is summer and less directly where it is winter.